xml如何解压java。尼奥。使用JAXB的路径？

Question

我一直在尝试使用JAXB解压一些xml，但我不断收到错误：

java.nio.file.Path is an interface, and JAXB can't handle interfaces.

有没有办法告诉JAXB如何从字符串构建路径

我的班级：

@XmlRootElement
public class Project extends OutputConfiguration {
    private Path sourceDir;
    private Path buildDir;
    private String name;

    /**
     * Get the root directory of the sources.
     * This will be used as the working directory for the build.
     *
     * @return the path
     */
    public Path getSourceDir() {
        return sourceDir;
    }

    /**
     * Get the root directory of the sources.
     *
     * @param sourceDir the path
     */
    @XmlElement
    public void setSourceDir(Path sourceDir) {
        this.sourceDir = sourceDir;
    }

    /**
     * Get the build directory.
     * This is the directory where all outputs will be placed.
     *
     * @return the path
     */
    public Path getBuildDir() {
        return buildDir;
    }

    /**
     * Set the build directory.
     *
     * @param buildDir this is the directory where all outputs will be placed.
     */
    @XmlElement
    public void setBuildDir(Path buildDir) {
        this.buildDir = buildDir;
    }

    /**
     * Get the friendly name of the project.
     *
     * @return the name of the project
     */
    public String getName() {
        return name;
    }

    /**
     * Set the friendly name of the project.
     *
     * @param name the name
     */
    @XmlElement(required = true)
    public void setName(String name) {
        this.name = name;
    }
}

我创建了一个ObjectFactory类，它调用默认构造函数并设置一些默认值

Answer 1

你要找的是XmlAdapter和@XmlJavaTypeAdapter

您必须创建一个扩展XmlAdapter的类，比如XmlPathAdapter，实现抽象方法，然后需要使用@XmlJavaTypeAdapter（XmlPathAdapter.class）注释路径获取程序或字段

请参阅XmlAdapter文档以获取更多详细信息： http://docs.oracle.com/javaee/5/api/javax/xml/bind/annotation/adapters/XmlAdapter.html

Answer 2

这有两个部分，这两个部分都是工作所必需的：

---

由于java.nio.file.Path is an interface, and JAXB can't handle interfaces.错误，无法创建XmlAdapter<String, Path>。因此，您必须使用XmlAdapter<String, Object>，因为Object是Path的超类，所以它是有效的：

public class NioPathAdaptor extends XmlAdapter<String, Object> {
    public String marshal(Object v) {
        if (!(v instanceof Path)) {
            throw new IllegalArgumentException(...);
        ...

---

然后必须在属性上使用非常特定的@XmlElement和@XmlJavaTypeAdapter：

@XmlJavaTypeAdapter(NioPathAdaptor.class)
@XmlElement(type = Object.class)
private Path sourceDir;

type = Object.class告诉JAXB将其序列化，就好像它是一个Object，@XmlJavaTypeAdapter表示对该特定字段使用该特定的Object适配器，而不是另一个更通用的适配器